The present invention relates to a radioactive emission detector equipped with a position tracking system. More particularly, the present invention relates to the functional integration of a radioactive emission detector equipped with a position tracking system as above with medical three-dimensional imaging modalities and/or with guided minimal-invasive surgical instruments. The present invention is therefore useful for calculating the position of a concentrated radiopharmaceutical in the body in positional context of imaged portions of the body, which information can be used, for example, for performing an efficient minimally invasive surgical procedure. The present invention further relates to a surgical instrument equipped with a position tracking system and a radioactive emission detector for fine in situ localization during resection and/or biopsy procedures, which surgical instrument is operated in concert with other aspects of the invention.
The use of minimally invasive surgical techniques has dramatically affected the methods and outcomes of surgical procedures. Physically cutting through tissue and organs to visually expose surgical sites in conventional “open surgical” procedures causes tremendous blunt trauma and blood loss. Exposure of internal tissues and organs in this manner also dramatically increases the risk of infection. Trauma, blood loss, and infection all combine to extend recovery times, increase the rate of complications, and require a more intensive care and monitoring regiment. The result of such open surgical procedures is more pain and suffering, higher procedural costs, and greater risk of adverse outcomes.
In contrast, minimally invasive surgical procedures cause little blunt trauma or blood loss and minimize the risk of infection by maintaining the body's natural barriers to infection substantially intact. Minimally invasive surgical procedures result in faster recoveries and cause fewer complications than conventional surgical procedures. Minimally invasive procedures, such as laparoscopic, endoscopic, or cystoscopic surgeries, have replaced more invasive surgical procedures in all areas of surgical medicine. Due to technological advancements in areas such as fiber optics, micro-tool fabrication, imaging and material science, the physician performing the operation has easier-to-operate and more cost effective tools for use in minimally invasive procedures. However, there still exist a host of technical hurdles that limit the efficacy and increase the difficulty of minimally invasive procedures, some of which were overcame by the development of sophisticated imaging techniques. As is further detailed below the present invention offers a yet further advantage in this respect.
U.S. Pat. No. 5,846,513 teaches a system for detecting and destroying living tumor tissue within the body of a living being. The system is arranged to be used with a tumor localizing radiopharmaceutical. The system includes a percutaneously insertable radiation detecting probe, an associated analyzer, and a percutaneously insertable tumor removing instrument, e.g., a resectoscope. The radiation detecting probe includes a needle unit having a radiation sensor component therein and a handle to which the needle unit is releasably mounted. The needle is arranged to be inserted through a small percutaneous portal into the patient's body and is movable to various positions within the suspected tumor to detect the presence of radiation indicative of cancerous tissue. The probe can then be removed and the tumor removing instrument inserted through the portal to destroy and/or remove the cancerous tissue. The instrument not only destroys the tagged tissue, but also removes it from the body of the being so that it can be assayed for radiation to confirm that the removed tissue is cancerous and not healthy tissue. A collimator may be used with the probe to establish the probe's field of view.
The main limitation of this system is that once the body is penetrated, scanning capabilities are limited to a translation movement along the line of penetration.
An effective collimator for gamma radiation must be several mm in thickness and therefore an effective collimator for gamma radiation cannot be engaged with a fine surgical instrument such as a surgical needle. On the other hand, beta radiation is absorbed mainly due to its chemical reactivity after passage of about 0.2-3 mm through biological tissue. Thus, the system described in U.S. Pat. No. 5,846,513 cannot efficiently employ gamma detection because directionality will to a great extent be lost and cannot efficiently employ beta radiation because too high proximity to the radiative source is required, whereas body tissue limits the degree of maneuvering the instrument.
The manipulation of soft tissue organs requires visualization techniques such as computerized tomography (CT), fluoroscopy (X-ray fluoroscopy), magnetic resonance imaging (MRI), optical endoscopy, mammography or ultrasound which distinguish the borders and shapes of soft tissue organs or masses. Over the years, medical imaging has become a vital part in the early detection, diagnosis and treatment of cancer and other diseases. In some cases medical imaging is the first step in preventing the spread of cancer through early detection and in many cases medical imaging makes it possible to cure or eliminate the cancer altogether via subsequent treatment.
An evaluation of the presence or absence of tumor metastasis or invasion has been a major determinant for the achievement of an effective treatment for cancer patients. Studies have determined that about 30% of patients with essentially newly diagnosed tumor will exhibit clinically detectable metastasis. Of the remaining 70% of such patients who are deemed “clinically free” of metastasis, about one-half are curable by local tumor therapy alone. However some of these metastasis or even early stage primary tumors do not show with the imaging tools described above. Moreover often enough the most important part of a tumor to be biopsed or surgically removed is the active, i.e., growing part, whereas using only conventional imaging cannot distinguish this specific part of a tumor from other parts thereof and/or adjacent non affected tissue.
A common practice in order to locate this active part is to mark it with radioactivity tagged materials generally known as radiopharmaceuticals, which are administered orally or intravenously and which tend to concentrate in such areas, as the uptake of such radiopharmaceuticals in the active part of a tumor is higher and more rapid than in the neighboring tumor tissue. Thereafter, a radiation emission detector, typically an invasive detector, is employed for locating the position of the active area.
Medical imaging is often used to build computer models which allow doctors to, for example, guide exact radiation in the treatment of cancer, and to design minimal invasive or open surgical procedures. Moreover, imaging modalities are also used to guide surgeons to the target area inside the patient's body, in the operation room during the surgical procedure. Such procedures may include, for example, biopsies, inserting a localized radiation source for direct treatment of a cancerous lesion, known as brachytherapy (so as to prevent radiation damage to tissues near the lesion), injecting a chemotherapy agent into the cancerous site or removing a cancerous or other lesions.
The aim of all such procedures is to pin-point the target area as precisely as possible in order to get the most precise biopsy results, preferably from the most active part of a tumor, or to remove such a tumor in it's entirety on the one hand with minimal damage to the surrounding, non affected tissues, on the other hand.
However, in the current state of the prior art this goal is yet to be achieved, most of the common imaging modalities such as fluoroscopy, CT, MRI, mammography or ultrasound demonstrate the position and appearance of the entire lesion with anatomical modifications that the lesion causes to it's surrounding tissue, without differentiating between the non-active mass from the physiologically active part thereof.
On the other hand, prior art radiation emission detectors and/or biopsy probes, while being suitable for identifying the location of the radiation site, they leave something to be desired from the standpoint of facilitating the removal or other destruction of the detected cancerous tissue with minimum invasion of the patient.
The combination of modalities, as is offered by the present invention, can reduce the margin of error in positioning such tumors. In addition, the possibility of demonstrating the position of the active part of a tumor superimposed on a scan from an imaging modality that shows the organ or tumor, coupled with the possibility to follow a surgical tool in reference to the afflicted area during a surgical procedure will allow for a more precise and controlled surgical procedures to take place, minimizing the aforementioned problems.
The present invention addresses these and other issues which are further elaborated herein below, and offers the physicians and patients more reliable targeting, that in turn will result in less invasive and less destructive surgical procedures.